When corporations connect their internal computer networks with the Internet, there is a risk that the corporate networks may be accessed by unauthorized parties via the Internet. Due to the Internet's openness, parties on the Internet may easily get into the corporate networks and obtain internal data of the corporations absent some protective measures being in place. Thus, corporations often employ a firewall to protect their networks from unauthorized access from the Internet.
A firewall is a system that limits network access between two or more networks. A firewall typically resides in between the Internet and corporate networks and filters all traffic to and from the corporate networks. The firewall may allow anyone on the corporate networks to access the Internet, but stop unauthorized parties from gaining access to the corporate networks. Multiple firewalls may be employed in parallel to be able to handle an increasing amount of traffic to and from the corporate networks. When multiple firewalls are employed, the firewalls need to be load balanced for the efficient processing of the traffic. Typically, a first physical device is employed to load balance on the side of the firewalls that is interfaced with the Internet or other untrusted network and a second physical device is employed to load balance on the side of the firewalls that interface with trusted network.